Water going waves propagating towards and breaking near a shoreline have the potential to damage the shoreline if the energy from the waves is not dissipated. Typically, as a group of waves approach the shoreline, near a body of water such as a sea, a lake, a channel or shipping lane, the group of waves comes into contact with the water bottom. The group of waves will slow down and the wavelength of each wave will decrease. The energy of the wave is lost through contact with the water bottom. The shallower the water becomes the slower the wave moves, especially near the water bottom. As the wavelength decreases, the energy in the wave is transferred to increasing wave height. The steeper the water bottom gradient, the more pronounced the wave height will increase as the wave approaches the shore. Wave height will begin to increase when a wave experiences depths of around one half of its wavelength.
As a wave moves into increasingly shallow water, the bottom of the wave decreases in speed to a point where the top of the wave overtakes it and spills forward. The forward spilling of the wave breaks the wave, dissipating its energy at a rate consistent with the slope of the water bottom and head or tail winds. Generally, a wave begins to break when the wavefront reaches a water depth of about 1.3 times the wave height. After a wave breaks, the wave amplitude lessens as the energy is dissipated into eddy currents and turbulent flow.
Lower energy waves that do not naturally break can also cause damage. For example, ships moving through a shipping lane may create low energy waves that cause erosive effects on the nearby shoreline.
The prior art has attempted to address these problems with limited success. For example, U.S. Pat. No. 905,596 to Smith discloses a sea wall that includes a series of blocks that have cells or cavities on their exposed faces, permanent, entrenched, affixed to the land. However, the seawall cannot be deployed in the water and must be affixed to the land, thereby increasing the cost for installation. Further, the seawall does not allow fish or other sea animals to pass through, thereby requiring time consuming maintenance.
U.S. Pat. No. 4,498,805 to Weir discloses a breakwater for protecting a bank or bluff from erosion that comprises a plurality of similar modules resting on the ground bed below the water. Each module has a single, large, upwardly concave trough to absorb wave energy. The modules are tied together by a pair of cables extending through pairs of pipes embedded in the bases of the respective modules. However, the breakwater modules must be assembled in a straight line and cannot be deployed to conform to the contours of the shoreline.
U.S. Pat. No. 4,978,247 to Lenson discloses a modular erosion control breakwater device placed on the beach floor of a body of water. The device has a body portion having a first surface defining a seaward face and oppositely disposed therefrom a second surface defining a landward face. A plurality of holes extending between said first and second surfaces for the passage of water therethrough. However, the device in Lenson must be deployed in a straight line and cannot be deployed in a custom arrangement.
U.S. Pat. No. 5,697,736 to Veazey, et al. discloses an “L-wall”, which is an L-shaped structural member intended for use in retaining walls and seawalls. The L-wall has a vertical wall or stem portion substantially perpendicular to a footer, and vertical key extending below the lower surface of the footer, in line with the vertical wall portion. Holes are preferably formed in the vertical wall and footer portions to provide drainage for liquid collecting behind the retaining wall or seawall. Holes can also be placed to facilitate handling and temporary interconnection of the L-members as well as drainage. However, the L-wall in Veazey requires the structure to be anchored to land and cannot be deployed to mirror the shape of the shoreline.
The prior art does not disclose or suggest a modular wave-break that can conform the shoreline upon deployment. Therefore, there is a need in the prior art for a modular wave-break having a tapered base for a custom arrangement upon deployment.